无脊椎动物 Invertebrates
有脊椎和无脊椎动物
有脊椎动物 Vertebrates
- Mammals
- Birds
- Reptiles: turtles, tortoises, lizards, snakes, crocodilians
- Amphibians: frogs, toads, salamanders, newts
- Fish
无脊椎动物 Invertebrates
没有脊柱（backbone）。97%的动物都是无脊椎动物。
- Worms: flatworms, roundworms, segmented worms
- Arthropod (节肢动物): insects, centipedes, crabs, spiders, scorpions
- Mollusks (软体动物): slugs, snails, octopuses, squid, oysters, clams
- Echinoderms (棘皮动物): starfish
- Cnidarians (刺胞动物): jellyfish, hydroid(水螅) sea anemones(海葵) corals
Mollusks 软体动物
- slugs, snails, oysters, clams, octopuses, squid, cuttlefish.
- most have a soft body and muscular base called a foot. Many have protective shells and feed using a moving ribbon of teeth called radula.
Arthropods 节肢动物
- four out of five animal species are arthropods.
- insects, spiders and crabs.
Echinoderms 棘皮动物
- bodies are usually formed from five equal parts arranged in a circle.
- starfish, sea cucumber, urchin, feather star
Cnidarians 刺胞动物
- jellyfish, hydroid(水螅), sea anemones(海葵), corals
Coral reef: covering 1% of ocean floor but home to 25% of all marine creatures.
Worms
roundworms, segmented worms, flatworms.